Humans are acutely attuned to changes in their surrounding temperature and often seek means to make themselves more thermally comfortable. A person's temperature regulation may be accomplished by modifying the temperature of the surrounding atmosphere, like HVAC systems, or by applying a thermal regulation device, such as an icepack or a heat pad, to the user themselves. The use of personal thermoregulation devices allows a user to try to achieve a desired level of thermal comfort without interfering with other people around them. Additionally, it is economical and desirable to allow a user to adjust their own thermal comfort, as each person's thermal tolerance varies.
One of the most common devices used for thermoregulation of body temperature is a “cool vest.” These are vests that are worn by a user and absorb excess body heat, thereby keeping the user more comfortable. The vests may also serve a vital health role in ensuring a user's core temperature does not climb dangerously high as the user is performing a task in a hot environment. Such vests are often worn by surgeons in operating theaters, racecar drivers during races and other users who wish to maintain a comfortable or safe body temperature in an environment or while performing tasks. The cool vest may utilize either a passive or active cooling system. In the passive cooling form, the vest or inserts, such as gel ice packs, are chilled before being worn by a user.
As the vest is worn, the vest or inserts cools the user and help maintain user comfort and body temperature. The vests in a passive cooling form are limited in duration and ability to remove excess user heat since they lack a means to maintain their cool state. As the vest or inserts absorb a user's heat, they themselves start to warm up thereby lessening the cooling affect the user experiences. If the cooling means are in the form of the inserts, the inserts can be replaced as their efficacy wanes, but the user would be required to have access to pre-chilled inserts when replacement is necessary. Often the passive cooling vests are cheaper than active cooling vests since they are not required to have additional plumbing or wiring. In the active cooling form, the vest often features tubing through which a fluid may be circulated. As the fluid is circulated about the vest it absorbs body heat from the user, thus maintaining the user in a safe and/or comfortable temperature range. The fluid is often chilled and recirculated once it exits the vest. The need to rechill the fluid and provide recirculation means the vest needs to be connected to such equipment. Often this is an insulated vessel that has some sort of heat exchanger submerged in a cold fluid or a refrigeration type unit. The constant circulation of continuously chilled fluid about the vest keeps the user in a cool and comfortable state. The drawbacks of these active cooling vests are that they are typically bulky and may require additional resources, such as power, to function. These drawbacks limit the portability and deployability of such vests due to their required infrastructure.
Another active cooling device are cool gloves. These are small device in which users place their hand, which grips a metal cylinder. A vacuum is pulled in the chamber causing the blood vessels of the user's hand to come to the surface where they contact the cool metal cylinder. The contact between the cylinder and the user's hand cools the user's blood. The metal cylinder is kept cool by pumping chilled water through it. These devices are smaller and more portable than a cool vest but are still somewhat bulky. Additionally, the user is incapable of using their hand while using the device.
Another method of thermoregulation used by many people is the use of gel packs or other contained substances that can be chilled or warmed before applying. These are applied and held or restrained against the user's skin where the user experiences coolness or warmth. As these devices are used, their efficacy wanes as they either warm up or cool down due to the user's own body heat.
There exists a need for a user wearable device that provides the user thermal comfort, either by heating or cooling and does not hinder the user and their movements.